This is the factory I visited last week.A. what B. whichC. where D. it

问题补充：

This is the factory I visited last week.

A. what

B. which

C. where

D. it

答案：

A. what

(答案→)B. which

C. where

D. it

解析：考查定语从句：先行词是the factory，定语从句中缺少宾语用that或which引导定语从句，句意：这是我上周参观的工厂。选B。